Crest or Alpine

In addition to my last post I'm still a little confused about the difference between Crest or Alpine rims. Whilst they are pretty similar in weight they have very distinct profiles.
For an average rider (trail centres, a bit of Dartmoor and a couple of 24's per year) weighing 73 kilos, which should I go for?
To put it another way, what effect does the profile have in each case.

I'm running Crests on my 29er with Schwalbe NN on the rear and Rocket Rons on the front. Over the last year I've only had one large burp and tyre off scenario but that was because I had about 15psi in the front! From what you describe as your trails, I'm on the same page but I'm a FB at 85KGs!

I've got Alpine rims (CX-ray spokes) and have often used them for general XC rides in the Dales (they've mostly been used on the canal commuting bike). I used them regularly for Dales XC in 2011, but not last summer very much as I was worried about the lightweight hubs in the crap weather last summer. I'm 13 stone, when they're on the bike I avoid jumps and drops or barrelling down big rocky tracks, but that's looking after them rather than knowing their limitations. I don't know the weight difference between the rims, but if it's negligible then probably go Crests.